package org.example.filter;

import io.jsonwebtoken.Claims;
import jakarta.servlet.*;
import jakarta.servlet.annotation.WebFilter;
import jakarta.servlet.http.HttpServletRequest;
import jakarta.servlet.http.HttpServletResponse;
import lombok.extern.slf4j.Slf4j;
import org.example.utils.CurrentHolder;
import org.example.utils.JwtUtils;

import java.io.IOException;

@Slf4j
@WebFilter(urlPatterns = "/*")
public class TokenFilter implements Filter {

    @Override
    public void doFilter(ServletRequest servletRequest, ServletResponse servletResponse, FilterChain filterChain) throws IOException, ServletException {
        HttpServletRequest  request = (HttpServletRequest) servletRequest;
        HttpServletResponse  response = (HttpServletResponse) servletResponse;

//        1.获取到请求路径
        String requestURI = request.getRequestURI();

//        2.判断是否是登录请求
        if (requestURI.contains("/login")) {
            log.info("登录请求，放行");
            filterChain.doFilter(request, response);
            return;
        }

//        3.获取请求头中的token
        String token = request.getHeader("token");

//        4.判断token是否存在，如果不存在，说明用户没有登录，返回错误信息（401状态码）
        if (token == null||token.isEmpty()) {
            log.info("用户未登录，请先登录");
            response.setStatus(HttpServletResponse.SC_UNAUTHORIZED);
            return;
        }

//        5.如果token存在，校验令牌，如果校验失败 -> 返回错误信息（401状态码）
        try{
            Claims claims =JwtUtils.parseToken(token);
            Integer employeeId = (Integer) claims.get("id");
            CurrentHolder.setCurrentId(employeeId);
            log.info("当前用户id为：{},将其存入ThreadLocal",employeeId);

        }catch (Exception e){
            log.info("令牌校验失败");
            response.setStatus(HttpServletResponse.SC_UNAUTHORIZED);
            return;
        }

//        6.校验通过，放行
        log.info("令牌校验通过");
        filterChain.doFilter(request, response);

        //7.删除ThreadLocal中的数据
        CurrentHolder.remove();
    }
}
